Light-emitting device, electronic apparatus including the light-emitting device, and condensed cyclic compound

Abstract

A light-emitting device, an electronic apparatus including the light emitting device, and a condensed cyclic compound represented by Formula 1. The light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer arranged between the first electrode and the second electrode, the interlayer including an emission layer. The emission layer includes an emitter and one or more host(s) of number m1, m1 is an integer of 1 or more, and if m1 is 2 or more, two or more of the hosts are different from each other, the emitter and the host(s) m1 are different from each other, the emitter includes a condensed ring in which two or more monocyclic groups are condensed with each other, at least one of the monocyclic groups is a 6-membered ring including a boron atom, a nitrogen atom, and a carbon atom as ring-forming atoms, and at least one of the protection coefficient of the boron atom in the emitter is 0.7 or more. Formula 1 provided herein.

What is claimed is: 
     
         1 . A light-emitting device comprising:
 a first electrode and a second electrode facing the first electrode; and   an interlayer arranged between the first electrode and the second electrode, the interlayer comprising an emission layer,   wherein the emission layer comprises an emitter and one or more hosts of number m1, m1 is an integer of 1 or more, and if m1 is 2 or more, two or more of the hosts are each different from the other,   the emitter and the one or more hosts are each different from the other,   the emitter comprises a condensed ring with two or more monocyclic groups condensed to the other, and at least one of the two or more monocyclic groups is a 6-membered ring comprising a boron atom and a carbon atom as ring-forming atoms,   wherein a protection coefficient of the boron atom in the emitter is represented by Expression 1 and at least one of the protection coefficient of the boron atom is 0.7 or more:   
       
         
           
             
               
                 
                   
                     1 
                     - 
                     
                       ( 
                       
                         
                           A 
                           2 
                         
                         / 
                         
                           A 
                           1 
                         
                       
                       ) 
                     
                   
                 
                 
                   
                     Expression 
                     ⁢ 
                         
                     1 
                   
                 
               
             
           
         
         wherein, in Expression 1, 
         A 1  is a total surface area of a virtual sphere defined by a radial distance from the boron atom used in the determination of Expression 1 to an atom of the emitter furthest from the boron atom, 
         A 2  is an area of a region M 2  at the surface of the virtual sphere, wherein the region M 2  is a surface region defined by a plurality of projection lines from the boron atom without contacting a surface surrounding a virtual compound E having the same structure as the emitter except that the boron atom is not present, and 
         A 1  and A 2  are each evaluated by a density functional theory (DFT) calculation. 
       
     
     
         2 . The light-emitting device of  claim 1 , wherein the emission layer further comprises a sensitizer, and
 excitation energy in the emission layer is transferred from the sensitizer to the emitter and the emitter emits as fluorescence the excitation energy absorbed from the sensitizer.   
     
     
         3 . The light-emitting device of  claim 2 , wherein the fluorescence emitted from the emission layer has an emission peak wavelength in a range of about 400 nm to about 500 nm. 
     
     
         4 . The light-emitting device of  claim 1 , wherein at least one of the protection coefficient of the boron atom is in a range of about 0.72 to about 0.99. 
     
     
         5 . The light-emitting device of  claim 1 , wherein at least one of the protection coefficient of the boron atom is in a range of about 0.8 to about 0.99. 
     
     
         6 . The light-emitting device of  claim 1 , wherein the emitter satisfies at least one of Conditions A or B:
 Condition A   singlet (S 1 ) energy of the emitter is in a range of about 2.700 eV to about 3.050 eV;   Condition B   an absolute value of a difference between singlet (S 1 ) energy and triplet (T 1 ) energy of the emitter is in a range of 0 eV to about 0.415 eV.   
     
     
         7 . The light-emitting device of  claim 1 , wherein an emission peak wavelength of an emission spectrum of the emitter is in a range of about 400 nm to about 500 nm. 
     
     
         8 . The light-emitting device of  claim 1 , wherein the emitter comprises at least one group represented by Formula 2: 
       
         
           
           
               
               
           
         
         wherein, in Formula 2, 
         R 1  to R 10  are each independently: 
         hydrogen, deuterium, —F, or a cyano group; 
         a C 1 -C 60  alkyl group unsubstituted or substituted with deuterium, —F, a cyano group, or any combination thereof; or 
         a C 6 -C 60  aryl group unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 60  alkyl group, a C 6 -C 60  aryl group, or any combination thereof, 
         R 11  to R 13  are each independently: 
         hydrogen, deuterium, —F, or a cyano group; or 
         a C 1 -C 60  alkyl group unsubstituted or substituted with deuterium, —F, a cyano group, or any combination thereof, and 
         * indicates a binding site to the condensed ring comprised in the emitter. 
       
     
     
         9 . The light-emitting device of  claim 8 , wherein the group represented by Formula 2 comprises a tert-butyl group unsubstituted or substituted with deuterium. 
     
     
         10 . The light-emitting device of  claim 1 , wherein the emitter is a condensed cyclic compound represented by Formula 1: 
       
         
           
           
               
               
           
         
         wherein, in Formula 1, 
         Ar 0  is a group represented by Formula 2, 
       
       
         
           
           
               
               
           
         
         wherein, in Formulae 1 and 2, 
         ring Y 1 , ring Y 2 , and ring Y 3  are each independently a C 5 -C 60  carbocyclic group or a C 3 -C 60  heterocyclic group, 
         W 1  is a single bond, O, S, N(Ar 1 ), N(T 11 ), C(T 12 )(T 13 ), or Si(T 12 )(T 13 ), 
         W 2  is a single bond, O, S, N(Ar 2 ), N(T 21 ), C(T 22 )(T 23 ), or Si(T 22 )(T 23 ), 
         n1 and n2 are each independently 0 or 1, 
         when n1 is 0, *—(W 1 ) n1 —*′ is not present, 
         when n2 is 0, *—(W 2 ) n2 —*′ is not present, 
         the sum of n1 and n2 is 1 or more, 
         Ar 1  and Ar 2  are each a group represented by Formula 2, R 1  to R 10  are each independently: 
         hydrogen, deuterium, —F, or a cyano group; 
         a C 1 -C 60  alkyl group unsubstituted or substituted with deuterium, —F, a cyano group, or any combination thereof; or 
         a C 6 -C 60  aryl group unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 60  alkyl group, a C 6 -C 60  aryl group, or any combination thereof, 
         R 11  to R 13  are each independently: 
         hydrogen, deuterium, —F, or a cyano group; or 
         a C 1 -C 60  alkyl group unsubstituted or substituted with deuterium, —F, a cyano group, or any combination thereof, 
         * in Formula 2 indicates a binding site to Formula 1, 
         Z 1 , Z 2 , Z 3 , T 11 , T 12 , T 13 , T 21 , T 22 , and T 23  are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, —SF 5 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C 1 -C 60  alkyl group, a substituted or unsubstituted C 2 -C 60  alkenyl group, a substituted or unsubstituted C 2 -C 60  alkynyl group, a substituted or unsubstituted C 1 -C 60  alkoxy group, a substituted or unsubstituted C 1 -C 60  alkylthio group, a substituted or unsubstituted C 3 -C 10  cycloalkyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenyl group, a substituted or unsubstituted C 6 -C 60  aryl group, a substituted or unsubstituted C 6 -C 60  aryloxy group, a substituted or unsubstituted C 6 -C 60  arylthio group, a substituted or unsubstituted C 1 -C 60  heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q 1 )(Q 2 ), —Si(Q 3 )(Q 4 )(Q 5 ), —Ge(Q 3 )(Q 4 )(Q 5 ), —B(Q 6 )(Q 7 ), —P(═O)(Q 8 )(Q 9 ), —P(Q 8 )(Q 9 ), or a group represented by Formula 2, 
         b1 to b3 are each independently an integer from 0 to 10, 
         two or more of Z 1 , Z 2 , Z 3 , T 11 , T 12 , T 13 , T 21 , T 22 , and T 23  are optionally linked to each other to form a substituted or unsubstituted C 5 -C 30  carbocyclic group or a substituted or unsubstituted C 1 -C 30  heterocyclic group, 
         at least one substituent of the substituted C 5 -C 30  carbocyclic group, the substituted C 1 -C 30  heterocyclic group, the substituted C 1 -C 60  alkyl group, the substituted C 2 -C 60  alkenyl group, the substituted C 2 -C 60  alkynyl group, the substituted C 1 -C 60  alkoxy group, the substituted C 1 -C 60  alkylthio group, the substituted C 3 -C 10  cycloalkyl group, the substituted C 1 -C 10  heterocycloalkyl group, the substituted C 3 -C 10  cycloalkenyl group, the substituted C 1 -C 10  heterocycloalkenyl group, the substituted C 6 -C 60  aryl group, the substituted C 6 -C 60  aryloxy group, the substituted C 6 -C 60  arylthio group, the substituted C 1 -C 60  heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is each independently: 
         deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, or a C 1 -C 60  alkylthio group; 
         a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, or a C 1 -C 60  alkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 11 )(Q 12 ), —Si(Q 13 )(Q 14 )(Q 15 ), —Ge(Q 13 )(Q 14 )(Q 15 ), —B(Q 16 )(Q 17 ), —P(═O)(Q 18 )(Q 19 ), —P(Q 18 )(Q 19 ), or any combination thereof; 
         a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a C 1 -C 60  alkylthio group, a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 21 )(Q 22 ), —Si(Q 23 )(Q 24 )(Q 25 ), —Ge(Q 23 )(Q 24 )(Q 25 ), —B(Q 26 )(Q 27 ), —P(═O)(Q 28 )(Q 29 ), —P(Q 28 )(Q 29 ), or any combination thereof; 
         —N(Q 31 )(Q 32 ), —Si(Q 33 )(Q 34 )(Q 35 ), —Ge(Q 33 )(Q 34 )(Q 35 ), —B(Q 36 )(Q 37 ), —P(═O)(Q 38 )(Q 39 ), or —P(Q 38 )(Q 39 ); or 
         any combination thereof, and 
         Q 1  to Q 9 , Q 11  to Q 19 , Q 21  to Q 29 , and Q 31  to Q 39  are each independently: hydrogen; deuterium; —F; or a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a C 1 -C 60  alkylthio group, a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 60  alkyl group, a C 6 -C 60  aryl group, or any combination thereof. 
       
     
     
         11 . The light-emitting device of  claim 10 , wherein ring Y 1 , ring Y 2 , and ring Y 3  are each independently a benzene group, a naphthalene group, a phenanthrene group, a pyridine group, a pyrimidine group, a pyridazine group, a pyrazine group, a quinoline group, an isoquinoline group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a fluorene group, a dibenzosilole group, an azadibenzofuran group, an azadibenzothiophene group, an azacarbazole group, an azafluorene group, or an azadibenzosilole group. 
     
     
         12 . The light-emitting device of  claim 10 , wherein Z 1 , Z 2 , Z 3 , T 11 , T 12 , T 13 , T 21 , T 22 , and T 23  are each independently:
 hydrogen, deuterium, —F, or a cyano group;   a C 1 -C 20  alkyl group, a phenyl group, a biphenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a fluorenyl group, or a dibenzosilolyl group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 20  alkyl group, a phenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a fluorenyl group, a dibenzosilolyl group, or any combination thereof; or   —N(Q 1 )(Q 2 ), and   Q 1  and Q 2  are each independently a C 1 -C 20  alkyl group, a phenyl group, a biphenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a fluorenyl group, or a dibenzosilolyl group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 20  alkyl group, a phenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a fluorenyl group, a dibenzosilolyl group, or any combination thereof.   
     
     
         13 . The light-emitting device of  claim 10 , wherein Formula 1 satisfies at least one of Conditions 1 and 2:
 Condition 1   b1 is 1 or more, and at least one of Z 1  in the number of b1 comprises a carbazole group   Condition 2   b2 is 1 or more, and at least one of Z 2  in the number of b2 comprises a carbazole group.   
     
     
         14 . The light-emitting device of  claim 10 , wherein b3 is 1 or more, and at least one of Z 3  in the number of b3 is a C 1 -C 60  alkyl group that is unsubstituted or substituted with deuterium, —F, a cyano group, or any combination thereof. 
     
     
         15 . The light-emitting device of  claim 10 , wherein the emitter is a compound represented by Formula 1A: 
       
         
           
           
               
               
           
         
         wherein, in Formula 1A, 
         W 1  is O, S, N(Ar 1 ), N(T 11 ), C(T 12 )(T 13 ), or Si(T 12 )(T 13 ), 
         Ar 0 , Ar 1 , and T 11 , T 12 , and T 13  are each as defined in  claim 10 , 
         Z 11  and Z 12  are each defined as in connection with Z 1  in  claim 10 , and 
         Z 21  and Z 22  are each defined as in connection with Z 2  in  claim 10 . 
       
     
     
         16 . The light-emitting device of  claim 15 , wherein Formula 1A satisfies at least one of Conditions 3 to 5:
 Condition 3   at least one of Z 11  and Z 12  is an N-carbazolyl group unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 20  alkyl group, a phenyl group, or any combination thereof   Condition 4   at least one of Z 21  and Z 22  is an N-carbazolyl group unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 20  alkyl group, a phenyl group, or any combination thereof   Condition 5   Z 3  is a C 1 -C 20  alkyl group unsubstituted or substituted with deuterium, —F, a cyano group, or any combination thereof.   
     
     
         17 . The light-emitting device of  claim 2 , wherein the sensitizer is an organometallic compound,
 the organometallic compound comprises a transition metal and a tetradentate ligand bonded to the transition metal,   the transition metal is platinum or palladium, and   the tetradentate ligand comprises a carbene moiety bonded to the transition metal.   
     
     
         18 . An electronic apparatus comprising the light-emitting device of  claim 1 . 
     
     
         19 . A condensed cyclic compound represented by Formula 1: 
       
         
           
           
               
               
           
         
         wherein, in Formula 1, Ar 0  is a group represented by Formula 2, 
       
       
         
           
           
               
               
           
         
         wherein, in Formulae 1 and 2, 
         ring Y 1 , Y 2 , and ring Y 3  are each independently a C 5 -C 60  carbocyclic group or a C 3 -C 60  heterocyclic group, 
         W 1  is a single bond, O, S, N(Ar 1 ), N(T 11 ), C(T 12 )(T 13 ), or Si(T 12 )(T 13 ), 
         W 2  is a single bond, O, S, N(Ar 2 ), N(T 21 ), C(T 22 )(T 23 ), or Si(T 22 )(T 23 ), 
         n1 and n2 are each independently 0 or 1, 
         when n1 is 0, *—(W 1 ) n1 —*′ is not present, 
         when n2 is 0, *—(W 2 ) n2 —*′ is not present, 
         the sum of n1 and n2 is 1 or more, and 
         Ar 1  and Ar 2  are each a group represented by Formula 2, 
         R 1  to R 10  are each independently: 
         hydrogen, deuterium, —F, or a cyano group; 
         a C 1 -C 60  alkyl group unsubstituted or substituted with deuterium, —F, a cyano group, or any combination thereof; or 
         a C 6 -C 60  aryl group unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 60  alkyl group, a C 6 -C 60  aryl group, or any combination thereof, 
         R 11  to R 13  are each independently: 
         hydrogen, deuterium, —F, or a cyano group; or 
         a C 1 -C 60  alkyl group unsubstituted or substituted with deuterium, —F, a cyano group, or any combination thereof, 
         * in Formula 2 indicates a binding site to Formula 1, 
         Z 1 , Z 2 , Z 3 , T 11 , T 12 , T 13 , T 21 , T 22 , and T 23  are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, —SF 5 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C 1 -C 60  alkyl group, a substituted or unsubstituted C 2 -C 60  alkenyl group, a substituted or unsubstituted C 2 -C 60  alkynyl group, a substituted or unsubstituted C 1 -C 60  alkoxy group, a substituted or unsubstituted C 1 -C 60  alkylthio group, a substituted or unsubstituted C 3 -C 10  cycloalkyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenyl group, a substituted or unsubstituted C 6 -C 60  aryl group, a substituted or unsubstituted C 6 -C 60  aryloxy group, a substituted or unsubstituted C 6 -C 60  arylthio group, a substituted or unsubstituted C 1 -C 60  heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q 1 )(Q 2 ), —Si(Q 3 )(Q 4 )(Q 5 ), —Ge(Q 3 )(Q 4 )(Q 5 ), —B(Q 6 )(Q 7 ), —P(═O)(Q 8 )(Q 9 ), —P(Q 8 )(Q 9 ), or a group represented by Formula 2, 
         b1 to b3 are each independently an integer from 0 to 10, 
         two or more of Z 1 , Z 2 , Z 3 , T 11 , T 12 , T 13 , T 21 , T 22 , and T 23  are optionally linked to each other to form a substituted or unsubstituted C 5 -C 30  carbocyclic group or a substituted or unsubstituted C 1 -C 30  heterocyclic group, 
         at least one substituent of the substituted C 5 -C 30  carbocyclic group, the substituted C 1 -C 30  heterocyclic group, the substituted C 1 -C 60  alkyl group, the substituted C 2 -C 60  alkenyl group, the substituted C 2 -C 60  alkynyl group, the substituted C 1 -C 60  alkoxy group, the substituted C 1 -C 60  alkylthio group, the substituted C 3 -C 10  cycloalkyl group, the substituted C 1 -C 10  heterocycloalkyl group, the substituted C 3 -C 10  cycloalkenyl group, the substituted C 1 -C 10  heterocycloalkenyl group, the substituted C 6 -C 60  aryl group, the substituted C 6 -C 60  aryloxy group, the substituted C 6 -C 60  arylthio group, the substituted C 1 -C 60  heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is each independently: 
         deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, or a C 1 -C 60  alkylthio group; 
         a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, or a C 1 -C 60  alkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 11 )(Q 12 ), —Si(Q 13 )(Q 14 )(Q 15 ), —Ge(Q 13 )(Q 14 )(Q 15 ), —B(Q 16 )(Q 17 ), —P(═O)(Q 18 )(Q 19 ), —P(Q 18 )(Q 19 ), or any combination thereof; 
         a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a C 1 -C 60  alkylthio group, a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 21 )(Q 22 ), —Si(Q 23 )(Q 24 )(Q 25 ), —Ge(Q 23 )(Q 24 )(Q 25 ), —B(Q 26 )(Q 27 ), —P(═O)(Q 28 )(Q 29 ), —P(Q 28 )(Q 29 ), or any combination thereof; 
         —N(Q 31 )(Q 32 ), —Si(Q 33 )(Q 34 )(Q 35 ), —Ge(Q 33 )(Q 34 )(Q 35 ), —B(Q 36 )(Q 37 ), —P(═O)(Q 38 )(Q 39 ), or —P(Q 38 )(Q 39 ); or 
         any combination thereof, and 
         Q 1  to Q 9 , Q 11  to Q 19 , Q 21  to Q 29 , and Q 31  to Q 39  are each independently: hydrogen; deuterium; —F; or a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a C 1 -C 60  alkylthio group, a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 60  alkyl group, a C 6 -C 60  aryl group, or any combination thereof. 
       
     
     
         20 . A method of evaluating a protection coefficient of an atom X comprised in a compound Y, comprising:
 (a) evaluating A 1  by using a density functional theory calculation, wherein A 1  is a total area of a surface of a virtual sphere having a radial distance between the atom X in the compound Y and an atom furthest from the atom X among the atoms of the compound Y,   (b) evaluating A 2  by using a density functional theory calculation, wherein A 2  is an area of a region M 2  at the surface of the virtual sphere and the region M 2  is a surface region defined by a plurality of projection lines from the atom X without contacting a surface surrounding a virtual compound YE having the same structure as the compound Y except that the atom X is not present, and   (c) evaluating 1−(A 2 /A 1 ) to calculate the protection coefficient of the atom X.